Electric-power hammer



R. F. CIANFRONE.

ELECTRIC POWER HAMMER.

APPLICATION FILED MAY 16, 1918.

1,357,613. Patented NOV. 2, 1920.

2 SHEETS-SHEET I.

E m ueutoz R. F. CIANFRONE.

ELECTRIC POWER HAMMER.

APPLICATION FILED MAY I6. 1918.

1 35 7, 6 1 3 Patented Nov. 2, 1920.

2 SHEETS-SHEE 1' 2.

an uemto'c Cre'anf-Qone Warm) ed UNITED STATES PATENT OFFICE.

ELECTRIC-POWER HAMMER.

Specification of Letters latent.

Patented N 0V. 2, 1920.

Application filed May 1s, 1.918. SeriaI No. 234,946.

To all whom it may concern:

Be it known that I, RALPH F. CIANF ONI J, a citizen of the UnitedStates,residing at West New York, in the county of Hudson, State of New Jersey, have invented certain new and useful Improvements in Electric- Power Hammers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it ap'pertains to make and use the same.

My invention relates to new and useful improvements in power hammers and it is directed more particularly to the provision of an electrically operated hammer provided with a pair of electrodes adapted for alternate operation to procure operative recip-' rocation of the hammer member.

It is in general the object of my invention to simplify the structure and to increase the efliciency of devices of this character, and it is more particularly my object to provide an exceedingly compact hammer which may be most readily manipulated and which is adapted for stone cutting and other operations.

A further and important object resides in the inclusion of a rheostat in the hammer, whereby the force of the strokes of the hammer may be varied at will by the operator.

lVith the above and other objects and advantages in view, the invention resides more particularly in the novel combination, formation and arrangement of parts hereinafter specifically described and pointed out in the appended claims.

In the accompanying drawing Figure l is an elevational view of an electric power hammer constructed in accordance with the present invention,

Fig. 2 is a longitudina' sectional view taken centrally through th hammer,

Fig. 3 is an enlarged sectdgnal View of the rheostat structure dispose end of the hammer,

Fig. 4 is a diagrammatic view of the wiring circuits of the hammer,

Fig. 5 is an enlarged sectional view of the movable contacts of the hammer,

Fig. 6 is a transverse sectional view taken in the rear I through the rheostat structure on the line 66 of Fig. 2,

Fig. 7 is a transverse sectional view taken through the rheostat structure on the line mer, and

Fig. 9 is a rear end view of the hammer.

Referring now more particularly to the drawings, there is provided a cylindrical main casing 5 which, at the forward or working end of the hammer is closed by a conical head 6 provided with a central longitudinal tool receiving passage 7, the inner portion of which is reduced and communicates with the interior of the casing for reception of the working end of the hammer element. The other end of the casing is counter bored and threaded internally for the reception of a cap 8 carrying the rheostat structure.

Disposed in the casing, with their inner ends separated a distance substantially equal to the stroke of the hammer element, are.'sol'enoids 9 and 10, preferably having their bores lined with sleeves 11. The solenoid 9 seats against the head 6, and disposed between the solenoids are substantially semi-circular spacing members 12 having their side edges spaced apart to form diametrically opposed guide slots for the contact head of the hammer element. The hammer element comprises a cylindrical body 13 slidable in the sleeve 11 of the solenoid 9 and having its working end reduced at 14 to engage in the reduced portion of the head passage 7, the consequent shoulder 15, formed at the juncture of the reduced portion with the, body, serving by abutting contact with the head 6 to limit the working stroke of the hammer element. The sleeve of the solenoid 10 is of smaller diameter than the sleeve of the solenoid 9 and slidable in the sleeve of the solenoid 10 is a cylindrical core member 16 which is threadedly engaged in a socket 17 of the body member 13, which forms the core of the work-stroke solenoid 9. Thus upon alternate; energizations of the solenoids, the

hammer element will be reciprocated to operate a tool member disposed in the head passage 7.

For procuring this alternate energization of the solenoids, a bar 18,0f conducting material is supported longitudinally of the casing in one side of the space between the solenoids, by engagement of its reduced ends in the adjacent end plates 19 of the solenoids, this plate being disposed opposite one of the guide slots formed by the spacing members 12. Adjacent the other guide slot formed by said members, a bar 20 of insulating material is supported in a similar manner, and this bar carries contact mem- 'bers 21 and 22 at its end portions,.the contact member 22 being disposed "adjacent the solenoid 9. Within the space between the solenoids, the hammer body 13 is provided with an armature head 23 which slidably fits within the semi-circular spacing memducting material carrying contact blocks hers 12, and projecting at diametrically.

30, and rods 31 extend inwardly from the cups 29 through the bases of the insulating cups 26 and are slidably engaged in the sleeve 28. An expansive spring 32 is. dis

posedin the sleeve 28 between the inner ends of these rods, and thus normally urges said rods and the contact blocks outwardly for sliding engagement with the bars 18 and 20;

By this spring also a continuous contact is afiorded between the contact blocks. Thus,

in reciprocation of the hammer element, the blocks 30 are always in electrical connection with the bar 18, and alternately are in circuit with the contacts 21 and 22 whereby as will be hereinafter more clearly shown, the solenoids are alternatively energized.

.The cap carried rheostat structure comprises concentric series of alternate conduct ing and insulating rings 33 and 34 respectively, disposed in the mouth portion of the cap, with their peripheries secured in contacting relation whereby to close the mouth of the cap, one of the insulating rings 34 being disposed outermost, and the rings 33 being mutually connected as shown diagrammatically in Fig. 4. Disposed against the upper edges of the rin s is an insulating plate 35 and projecting rom the rings 33 through said plate are a series of contact studs 36, arranged in spiral relation as shown particularly in Fig. 6. A core block Slidable 37 is disposed axially in the cap and is held by engagement in an innermost insulating ring 34. Rotatably mounted on this block is a plate 38 through which is passed a binding post 39 forming also a pivot for the plate. The plate has a radial contact rib 38 adapted for selective contact with the studs 36. Rotation of the plate is procured by a handle 40 projecting upwardly therefrom through an arcuate slot 41 in the end of the cap 8. Operation of the rheostat may be thus effected in a most ready manner by an operator holding the hammer in working position, it being noted that setting the contact rib in engagement with .a stud 42 carried on the plate 35 and insulated from the rings, serves to entirely break the operating circuit.

The central portion of the cap 8 is outwardly offset at 43'to provide a clearance space for the binding post 39 and a Wire 44 entering said oifset and formin one of the circuit Wires for the hammer. he other circuit wire 45 leading from the hammer also enters the offset portion 43 and is connected with one end of the coil of the solenoid 10, while a branch 46 thereof extends through a longitudinal passage 47 in the wall of the main casing 5, for connection with one end of the solenoid 9. A wire 48 connects the other end of the solenoid 10 with the contact 22 and a wire 49 connects the other end of the solenoid 9 with the contact 21. A wire 50 connects the outer ring 33 with the contact bar 18, and passes through a passage 51 in the wall of the casing, the connection of the wire 50 and ring being effected by a contact finger 52 insulated from and carried by the cap end of the main casing for engagement with the ring at the inward limit of screwing movement of the capv whereby the cap may be readily secured to or removed from the casing.

The wiring arrangement is shown more particularly in Fig. 4. The current passes through the wire 44, the contact plate and rib 38 and 38 one of the studs 36, a correlimit of movement at the end of its work stroke the current asses through the spring urged contact blocks 30 and their supporting sleeve structure to the contact '22 and from thence through the wire 48 to the retracting solenoid 10, to energize this solenoid and thus draw the hammer element to its inner limit of movement, the current passing from the solenoid through the common return wire 45. As the hammer element starts its return movement the circuit is broken by disengagement of the contacts 22 and 30 and the movement is completed by momentum of the hammer element. As the hammer element reaches the limit of inward movement the adjacent contact block 30 engages the contact 21 and a circuit is thus completed through the solenoid 9 and branch wire 46 to the common return wire 45, to impart sufiicient momentum to effect the Working stroke of the hammer element. Thus upon making contact through the rheostat structure a constant operative reciprocating movement of the hammer element is set up, and the rapidity and consequent force of this reciprocation is controlled by the amount of current, which latter may be in turn conveniently controlled by the rheostat structure. It is noted that-by reason of the successively varied diameters of the rheostat rings, they possess differential degrees of resistance. Thus, in the step-up actuation of the rheostat, the successive added amounts of current increase progressively to the full force, and this provides a finer degree of control of the lighter strokes of the hammer.

An exceedingly simple, durable and efficient electric hammer has thus been provided, which permits of a most flexible and convenient operation, whereby it is particularly adapted for such work as stone carv.

'ing wherein it is desired to impart a very rapid series of hammer blows with a short stroke.

' It is noted that the entire general structure permits a very ready assembly of the various parts of the hammer. It is further noted that the supporting sleeve 27 passes through theend of core 16 to prevent un-- threading movement thereof.

What is claimed, is:

1. An electric power hammer comprising a cylindrical casing having means for mounting a. tool in one end, a pair of solenoids within the casing with their inner end plates spaced from each other, spacers between said plates having longitudinal slots, a hammer element including cores within said solenoids and a head at the meeting ends 01": the cores movable within said spacers and having arms sliding in said slots, a power circuit branched to the solenoids, and means for switching current alternately to them, said means including elements carried by the arms and located outside the spacers.

2. An electric power hammer comprising a cylindrical casing having means mounting a tool in one end, a pair of solenoids within the casing, spacers between said solenoids having longitudinal slots, a hammerelcment including cores within said solenoids and a. head at the meeting ends of the cores movable within said spacers and having arms sliding in their slots, contacts on the outer ends of the arms, an element extending through the arms and head and maintaining said contacts in metallic connection, a power circuit branched to said for solenoids, and means for switching the current alternately to them, said means including other contacts with the casing outside said spacers and engaged by those on the arms as the hammer reciprocates.

3. In an electric power hammer, the combination with a cylindrical casing, two solenoids disposed therein and with their inner end plates spaced apart, and two semi-circular spacers between said end plates and with their ends spaced from each other to leave longitudinal slots of a core within one solenoid having an enlarged head within said spacers, a-core within the other solenoid, means for fastening its inner end within said head, the head having radial arms slidingin said slots, a power circuit branched to the solenoids, and means for switching it alternately to them, said means including contacts on the arms and in the casing outside the spacers.

4. In an electric power hammer, the combination with a cylindrical casing, two solenoids disposed therein, and two semi-circular spacers between said solenoids and With their ends spaced from each other to leave longitudinal slots; of a core within one solenoid having an enlarged head within said spacers, a core within the other solenoid, said head having a socket into which the inner end of the-last-named core projects and also havingradial arms slidable in said slots, an insulating sleeve passing longitudinally through the arms and intersecting the lastnamed core, a metallic element passing through this sleeve and having contacts at its extremities, contacts with the casing outside said spacers and with which those mentioned come into alternate engagement, a power circuit for the solenoids, and branches therefrom led through said contacts whereby the solenoids are alternately energized as the hammer reciprocates.

5. An electric power hammer including a pair of solenoids arranged in axial alinement, a hammer head slidably arranged in axial alinement with the solenoids, core memberscarried by the hammer head and movable in said solenoids, a rod passing transversely through and insulated from the hammer head, contacts supported by said rod and resiliently urged outward, a contact bar in constant engagement with one of said contacts, a pair of contacts for alternate engagement with the other hammer carried contact, and circuits including said contacts and the solenoids.

6. An electric power hammer including a cylindrical casing, tool holdingmeans at one end of the casing, a pair of solenoids in the casing coaxial therewith, circuits includ ing the solenoids, a hammer element-including core portions movable in the solenoids the solenoids defining guide slots between. their adjacent edges, arms on the hammer head movable in said slots, contacts on the arms and others carried Within the casing, and current reversing means for the circuits actuated by the alternate engagement of said contacts.

In testimony whereof E atfix my signature in the presence of three Witnesses.

. RALPH F. GIANFRONE. Witnesses:

M. MoDARELu, ARTHUR URDEIGA, 'DQMINIGK MAINIERY. 

